The purpose of the proposed research is to examine attentional dysfunction in schizophrenics. Schizophrenic attentional disturbances have been well documented in the psychiatric literature, but past research has accomplished little more than a relabeling of the attention deficit as heightened distractibility. Recently developed information processing models and experimental techniques which can examine the top-down versus bottom-up processing components of perception can be used to delve more deeply into the underlying nature of the schizophrenic attention dysfunction. The hypothesis to be tested is that schizophrenics, unlike normals, fail to rely on to-down expectation-driven processing for predictable stimuli, compromising their ability to process unpredictable stimuli. This hypothesis will be tested using a computerized visual information processing task which presents two words simultaneously under time-limited divided-attention conditions and measures the attentional processing of words appearing with O% versus 75% predictability. Hospitalized chronic schizophrenics who have been stabilized on medication and are sufficiently recovered from an acute phase to be ready for discharge will be compared to normal controls. The results are expected to show that, in contrast to normal attentional allocation which is based on stimulus predictability, schizophrenic attentional allocation is independent of predictability. Consequently, schizophrenics are expected to show none of the improvement in overall word identification performance that normals show with increasing predictability. Because they fail to rely on top-down expectation-driven processing for predictable stimuli, they fail to reserve sufficient attentional resources for the nonpredictable stimuli which require more bottom-up analysis. This experiment would thus provide empirical evidence for the disruption of attentional allocation in schizophrenics. In addition, this study will help to lay the foundation for a more comprehensive program of research on information processing abnormalities in psychiatric patients to be conducted over the longer term.